""Priscilla Oppenheimer"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > He didn't say that BGP negotiates the MTU in any of its PDUs. He just says > that mismatched MTUs can be a problem, which is all I mentioned in my > message about OSPF also (although OSPF does in fact also include the MTU in > database description packets and refuse to become adjacent with a router > that doesn't agree on the MTU).
That's what I'm talking about - OSPFv2 does in fact include an MTU field in its PDU's (Ok, Ok, it's not really a negotiation per se, but still...), so if somebody starts a discussion about MTU and BGP, then it would stand to reason that BGP includes an MTU field somewhere, which I am not aware of. And besides, the idea of MTU problems in BGP is an interesting one, because of the fact that BGP peering often occurs between non-adjacent routers. What is the relevant MTU size of such a peering arrangement? The routers do not share a common network, so is it really relevant to talk about MTU? > Did that have enough TLAs for you? ;-) I've read enough RFC's in my day to be impervious to TLA's. > > Priscilla > > At 09:53 PM 4/18/02, nrf wrote: > >Really? I had never heard of this problem. I'm not aware that BGP > >negotiates MTU in any of its PDU's. Can you provide the RFC that discusses > >this problem? > > > > > >""suaveguru"" wrote in message > >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > > If I am not wrong this problem also occurs for BGP > > > peers with unmatched MTU sizes which causes BGP to > > > flap when they exchange routing tables , especially if > > > one neighbour is configured with full-routes > > > > > > > > > regards, > > > > > > suaveguru > > > --- Priscilla Oppenheimer wrote: > > > > The problem happens when the routers try to exchange > > > > database description > > > > packets. One side can send packets that are too > > > > large for the other side to > > > > receive. Then the routers never achieve adjacency. > > > > It's an infamous > > > > problem. I was glad that Kevin brought it up. I was > > > > thinking we should have > > > > mentioned it in that other thread about OSPF Hellos > > > > (although this problem > > > > happens after the initial hellos). > > > > > > > > More here: > > > > > > > > http://www.cisco.com/warp/public/104/12.html > > > > > > > > Priscilla > > > > > > > > At 11:33 AM 4/17/02, Kane, Christopher A. wrote: > > > > > > The most frequently mismatched parameters > > > > relevant for OSPF > > > > > > configuration > > > > > > seem to be dead intervals & mtu sizes. > > > > > > > > > >OSPF doesn't care about MTU size. > > > > ________________________ > > > > > > > > Priscilla Oppenheimer > > > > http://www.priscilla.com > > > [EMAIL PROTECTED] > > > > > > > > > __________________________________________________ > > > Do You Yahoo!? > > > Yahoo! Tax Center - online filing with TurboTax > > > http://taxes.yahoo.com/ > ________________________ > > Priscilla Oppenheimer > http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=41911&t=41613 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
